Probing Gluon Helicity with Dijets from $\sqrt s$ = 510 GeV Polarized Proton Collisions at STAR

Suvarna Ramachandran
2016 Proceedings of XXIV International Workshop on Deep-Inelastic Scattering and Related Subjects — PoS(DIS2016)   unpublished
The production of jets in polarized proton collisions at STAR is dominated by quark-gluon and gluon-gluon scattering processes. The dijet longitudinal double-spin asymmetry (A LL ) is sensitive to the helicity distributions and may be used to extract information about the gluon helicity contribution ∆g(x, Q 2 ) to the spin of the proton. Previous STAR jet measurements at √ s = 200 GeV show evidence of polarized gluons for gluon momentum fractions above 0.05. The measurement of dijet A LL at √ s
more » ... = 510 GeV will extend the current constraints on ∆g(x, Q 2 ) to lower gluon momentum fractions and allow for the reconstruction of the partonic kinematics at leading order. These proceedings present preliminary results from the dijet A LL measurement from ∼ 50pb −1 of ∼ 50% polarized proton data taken during the 2012 RHIC run.
doi:10.22323/1.265.0231 fatcat:3zvmrdpbrfhvdalb5ueqfjlgce